After eight dives Monday, Hoyt said the vessel could date as far back as the late 1800s or early 1900s. The team determined the ship had a wooden hull and was steam-driven.

"We found the boiler, we found the fire bricks," Hoyt said. "If we had some more visibility ... we could get a lot more information."

The divers also found metal components, including rods, turnbuckles and pins.

Craig Hlavinka, of Matagorda, drove about three hours to participate in the dive.

"Well, it's a big, rusty mess," said Hlavinka, a volunteer with the historical commission. "It's always how they look at first."

Hoyt said the next step will be to figure out how old the vessel is. If the wreck predates 1900, it will automatically become a state archaeological landmark, according to the state's historical antiquities code. If the vessel is newer than that, it would be a candidate for consideration as a landmark.

Dee Wallace, of Port Aransas, one of the first to dive on the wreck, said he thinks it's an old steam barge.